Did I do the right thing

My 13 1/2 year old Maltese was throwing up a lot and became dehydrated. I took him to the emergency vet where he stayed fir 4 days on IV being treated for gastritis, aspiration pneumonia and an infection. He wouldn’t eat and I was told he had kidney disease. On the 3rd day the hospital asked me to stay with him to try to get him to eat, he would not, then they told me that he was pooping black material and they saw he developed bleeding ulcers. Since the first day I brought him in I asked multiple times if he was going to be ok and if I was being selfish putting him through all this at his aged. On the last night the ER vet finally confirmed that she was “Not Allowed” to tell me I may be time to end treatment and my dogs pain, but if that’s the where I was head I wasn’t wrong. Dexter is the first dog I’ve had since I was a young boy and I loved him more than life itself, I never had children so he was my son. Dexter and I had the better relationship than I ever could have asked for, it’s been 7 days now since I held him in my arms and ended his final ordeal. I still wonder if I did the right thing. Looking for advice. Dexter was a beautiful toy breed Maltese.